Pohl's ( Gateway ) newest interstellar adventure inverts many of SF's hoariest old chestnuts, polishing them until they shine like the stars to which his ships fly. Barry di Hoa, an antimatter engineer who works on the moon, is almost the archetypal ``scientist/hero'' except for the flaw of a strange chemical imbalance, which causes him to become a manic-depressive if he is not treated with esoteric drugs. Barry is just about to propose marriage to his girlfriend when his rival for her affections kidnaps him and sends him to the far-flung outpost of Pava, a multireligious melting pot. A quarter of Pava's settlers are the suicidal Millenarists who profess to believe that the world is so evil that everyone should kill themselves and thereby reduce the incidence of sin. Pohl takes the time-honored theme of evil religious fanatics standing in the way of progress and adds yet another cliche, that of the ``bug-eyed'' monster--here given a benign spin in the figure of a helpful and friendly caterpillar-shaped Lep alien named Geronimo, who becomes Barry's best friend. The colonists' religious problems, disturbances among the Lep labor force and Barry's personal ``madness'' all come to a head at the same time. Although the crisis has a simple solution, the slight skewing of familiar themes gives a piquant slant to the proceedings. The novel reminds the reader just how much fun these world-building stories can be, especially when they are written by a master like Pohl. (July)